非诺多泮和PBDA对兔冠状动脉和肾动脉cAMP产生系统影响的对比 …

3康? 研究多巴胺１（ＤＡ１）及多巴胺２（ＤＡ２）受体激动地兔冠状动脉及肾动脉腺苷酸环化酶（ＡＣ）活性的影响。方法 用放射免疫分析法测定ｃＡＭＰ含量,作为反映多巴胺受体功能的指标。结果 ＤＡ１受体激动剂非诺多泮及ＤＡ２受体激动剂ＰＢＤＡ均可剂量依赖性增加冠状动脉及肾动脉ｃＡＭＰＰＢＤＡ均可剂量依赖性增加冠状动脉及肾动脉ｃＡＭＰ生成量的增加,而ＤＡ２受体阻断剂ｄｏｍｐｅｒｉｄｏｎｅ则对ＰＢＤＡ的这一作

Effects of fenoldopam and PBDA on the cAMP generating system inrabbit coronary and renal arteries

AIM To study the effects of DA 1 and DA 2 receptor agonists on rabbit coronary and renal arteriesMETHODS cAMP levels were measured by radioimmunoassay as an index of dopamine receptor functionRESULTS Both the selective DA 1 receptor agonist,fenoldopam,and the DA 2 receptor agonist,propgl propylbutyldopamine(PBDA),induced a doserelated increases in cAMP formation in coronary and renal arteries;however,the magnitude of increase in the renal artery was remarkably greater than that in the coronary arteryThe stimulatory effect on AC activity of fenoldopam was significantly more potent than that of PBDAThe selective DA 1 receptor antagonist, SCH23 390, blocked fenoldopam and PBDAinduced cAMP production,while the selective DA 2 receptor antagonist,domperidone,was without effect on the increase of cAMP elicited by PBDACONCLUSION The existence of DA 1 receptors associated with stimulation of AC activity in both renal and coronary arteriesHowever,there are much fewer receptor sites in the coronary artery than in the renal artery,suggesting less physiological importance of such receptors in the coronary artery than in the renal artery